Experimental Infection 591 



observed in miliary tuberculosis. Sometimes there is uni- 

 versal enlargement of the lymphatic glands. Bacilli are 

 found in the blood and in all the internal organs. Skin 

 eruptions may occur during life, and upon the inner abdom- 

 inal walls petechiae and occasional hemorrhages may be 

 found. The intestine is hyperemic, the adrenals congested. 

 Serosanguinolent effusions may occur into the serous 

 cavities. 



Devell* has found frogs susceptible to the disease. 



Wyssokowitsch and Zabolotnyf found monkeys highly 

 susceptible to plague, especially when subcutaneously in- 

 oculated. When an inoculation was made with a pin dipped 

 in a culture of the bacillus, the puncture being made in the 

 palm of the hand or sole of the foot, the monkeys always 

 died in from three to seven days. In these cases the local 

 edema observed by Yersin did not occur. They point out 

 the interest attaching to infection through so insignificant a 

 wound and without local lesions. 



Klein { found that intraperitoneal injection of the bacillus 

 into guinea-pigs was of diagnostic value, producing a thick, 

 cloudy, peritoneal exudate rich in leukocytes and containing 

 characteristic chains of the plague bacillus, occurring in 

 from twenty-four to forty-eight hours. 



The plague bacillus may enter the body by inhalation from 

 an atmosphere through which it is disseminated, under 

 which circumstances it is usually of the pneumonic type, or 

 it may enter through the skin. Lesions too small to be seen 

 with the naked eye may suffice, and some have shown that 

 when the organisms are vigorously rubbed into the unbroken 

 skin, they may succeed in penetrating it. The pulmonary 

 or pneumonic form is not unlike other forms of pneumonia. 

 The lung is consolidated, enormous numbers of plague bacilli 

 occur in the sputum, the fever is high, and death occurs in a 

 few days. 



Cases in which the infection takes place through the skin 

 soon show swelling of the adjacent lymph-nodes. These 

 become very large and tense, occasion great suffering, and 

 finally may soften and evacuate if death from blood invasion 

 does not intervene. 



* "Centralbl. f. Bakt. u. Parasitenk.," Oct. 12, 1897. 

 t "Ann. de 1'Inst. Pasteur," Aug. 25, 1897, xi, 8, p. 665. 

 } "Centralbl. f. Bakt. u. Parasitenk.," xxi, No. 24, July 10, 1897, 

 p. 849. 



